Devices and methods for securing tissue

ABSTRACT

A compression ring to grip and compress body structure such as diverticulum, hemorrhoids, and tissue adjacent a hole. A resilient ring-shaped body defines a compression channel, and an elongated axially rigid gripping member extends diametrically across the through-opening. The gripping member can rest on a flange on the opposite side of the through-opening or engage with a second gripping member that extends diametrically across the through-opening from the opposite side of the ring. Or, a flexible cage structure can be disposed in the through-opening.

This application claims priority to U.S. provisional patent application61/492,289, filed Jun. 1, 2011 and incorporated herein by reference.This application is also a continuation in part of U.S. patentapplication Ser. No. 13/240,018, filed Sep. 22, 2011, which is acontinuation of U.S. patent application Ser. No. 12/141,391, filed Jun.18, 2008, now U.S. Pat. No. 8,062,308, which in turn claims priorityfrom U.S. provisional patent applications Ser. Nos. 60/982,083, filedOct. 23, 2007 and 61/012,124, filed Dec. 7, 2007. Priority is claimed toall of the above documents. U.S. Pat. No. 8,062,308 is incorporatedherein by reference.

FIELD OF THE INVENTION

The present application relates generally to devices and methods forsecuring tissue.

BACKGROUND

Internal body tissue sometimes must be secured together for variousreasons. As an example, diverticulosis is an unfortunately commoncondition in which an area of the intestine bulges out into theperitoneal cavity to form a sac referred to as a “diverticulum”. Theabove-referenced patent envisions a natural orifice method for resolvingdiverticulum by inverting them and then securing opposed serosalsurfaces together using a ring to thereby tightly and securely close offthe affected tissue to alleviate the risk of peritonitis.

While the patented approach is effective, present principles furtherunderstand that slippage of the ring can occur once it is placed ontissue. In the colon and bowel, for instance, significant peristalsisand pressure can stretch the tissue wall, which can force the ring offthe tissue, losing the therapeutic effect of the ring.

SUMMARY OF THE INVENTION

A ring for engaging tissue has a round resilient body defining an axialthrough-opening configured to receive the tissue. At least one elongatedaxially rigid gripping member extends diametrically across thethrough-opening. The gripping member has a first end embedded in thering and a second end distanced from the first end and not embedded inthe ring. The gripping member extends substantially entirely across thethrough-opening.

In one implementation, the gripping member rests on a flange attached toa portion of the through-opening opposite to where the gripping memberis embedded in the ring. In another example, the gripping member isfirst gripping member and the ring includes a second gripping memberthat extends diametrically across the through-opening from a portion ofthe ring opposite to where the gripping member is embedded in the ring.Each gripping member may be barbed in that each gripping member may beformed with a respective barb extending away from the other grippingmember. Or, the first gripping member can be flat and can include a hooksegment forming a bight, while the second gripping member can define along axis and can be twisted about the long axis. The second grippingmember likewise includes a hook forming a bight, and the bights of thegripping members face each other.

Yet again, in another embodiment the first gripping member is urgable bytissue through an eye formed in the second gripping member. Or, thefirst gripping member can be wider than the second gripping member, withthe gripping members being flushly disposed with each other throughouttheir length. In this last embodiment, first and second stabilizingelements can be formed on the ring in an orthogonal relationship to thegripping members, extending into the through-opening.

In another aspect, a ring for engaging tissue includes a round resilientbody defining an axial through-opening configured to receive the tissue,and a flexible cage structure disposed in the through-opening.

In another aspect, a method for making a tissue gripping ring includesforming at least one spike on a circular support, with the spikeextending inward relative to the circular support. The method includesovermolding a toroidal resilient ring onto the spike, removing the spikeand ring from the circular support, and removing excess ring materialfrom the spike.

In another aspect, a method for configuring a resilient ring forplacement in a patient to cause the ring to surroundingly grip tissue inthe patient includes engaging the ring with a first end of an expander.The expander tapers radially outwardly from the first end to acylindrical segment, with a diameter of the first end substantiallyequaling a diameter of the ring when the ring is in a relaxed state. Themethod contemplates pushing the ring along the expander to radiallystretch fee ring until the ring surrounds the cylindrical segment. Thecylindrical segment is juxtaposed with a carrying portion of a deliverydevice having substantially the same diameter as the cylindricalsegment, and then the ring is pushed from the cylindrical segment ontothe carrying portion to load the ring in a stretched state for deliveryto the tissue.

The details of the present invention, both as to its structure andoperation, can best be understood in reference to the accompanyingdrawings, in which like reference numerals refer to like parts, and inwhich:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a first embodiment of the present tissuering;

FIG. 2 is a perspective view of a second embodiment of the presenttissue ring;

FIG. 3A is a perspective view of a third embodiment of the presenttissue ring;

FIG. 3B is a top plan view of the third embodiment of the present tissuering showing an intermediate configuration of the gripping membersduring manufacture;

FIGS. 4-9 are various views of a fourth embodiment of the ring andstages of installing it in a patient;

FIGS. 10A and 10B are a perspective and cross-sectional view,respectively, of a fifth embodiment of the ring;

FIGS. 11-13D are views of a sixth embodiment of the ring;

FIGS. 14A-C show three alternate spike configurations prior tomanufacture;

FIGS. 15A-D show a series of ring configurations during manufacturing toillustrate an example method for making a ring according to presentprinciples;

FIGS. 16-19 show various stages of loading the ring onto a deliverydevice; and

FIG. 20 is a cross-sectional view showing an example mold with anexample ring therein to further illustrate methods for making the ring.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially to FIG. 1, a ring is shown, generally designated 10,which includes a disk-shaped or more preferably toroidal body 12 made ofresilient material such as silicone or other biocompatible resilientmaterial. Note that in general, the body is round with a centralopening, although non-limiting examples below disclose toroidal bodies.In the relaxed state shown, the ring 10 assumes a radially smallerconfiguration, and is resilient so that it can be stretched to aradially enlarged state to fit onto a delivery device as explainedfurther below. The ring is slid off the delivery device to engage tissuesuch as but not limited to a diverticulum to surround and compress thetissue. In the case of an inverted diverticulum as disclosed in theabove-referenced patent, it is compressed by the ring 10 in its invertedstate, and so is closed off serosa to serosa.

As shown in FIG. 1, the ring 10 also includes a spike design having abarb element to prevent backing out of the tissue once it has beeninstalled. With more specificity, the body 12 defines an axialthrough-opening 14 configured to receive the tissue, and one or more (inthe embodiment shown, two) elongated axially rigid gripping members 16which may be configured as spikes as shown in the example extenddiametrically across the through-opening, parallel to each other andside by side, i.e., are offset from each other in the radial dimensiondefined by the body. In one example embodiment, the gripping members aremade of stainless steel.

As shown, each gripping member 16 has a respective first end 18 embeddedin the ring and a second end 20 distanced from the first end and notembedded in the ring. In the example shown, the second end 20, which isa free end, is pointed, and extends almost to the body 12 but does notquite reach the body 12, thus extending substantially entirely acrossthe through-opening 14. In some examples, each gripping member 16extends at least past the longitudinal axis defined by the body 12, andpreferably extends to eighty percent (80%) of the way across thediameter of the through-opening 14. More preferably still, each grippingmember 16 extends to at least ninety percent (90%) of the way across thediameter of the through-opening 14.

In the example of FIG. 1, each gripping member 16 is barbed, in thateach gripping member is formed with a respective barb 22 extending awayfrom the other gripping member. Specifically describing an example barb,each gripping member 16 may have a straight inside edge 24 and anopposed outside edge 26, and the barb 22 is established by an extensionat the second end 20 of the gripping member 16 that has two opposed barbsurfaces 28, 30 extending outwardly away from the outside edge 26 at anacute angle thereto and tapering to a barb point 32. The inside edges 24of the gripping members face each other as shown.

Turning to FIG. 2, barbed spikes are shown wherein the barb structuresengage with each other and lock together. With greater specificity, aring 34 with a toroidal ring body 36 defines a through-opening 38, andfirst and second gripping members 40, 42 extend diametrically across theopening 38 side by side. i.e., are offset from each other in the radialdimension defined by the body. The gripping members 40, 42 are formed attheir respective free ends with respective hook segments 44, 46, eachforming, in concert with the rest of the gripping member, a respectivebight 48, 50. The first gripping member 40 is flat as shown, whereas thesecond gripping member defines a long axis and is twisted about the longaxis. The bights 48, 50 of the gripping members 40, 42 face each otherso that as tissue forces the gripping members 40, 42 together, the hooksegments engage with each other and under the force of the tissue locktogether.

Now considering FIGS. 3A and 3B, a spike design is shown with a nestingconfiguration. As will be explained shortly in further detail, onegripping member establishes a prong like structure and the oppositegripping member has a receptacle structure designed for receiving theopposing member. When the ring is applied to tissue, the ring is firststretched and the spikes rotated out parallel to the central axis of thering. When released onto the tissue, the spikes spontaneously rotateinwards to the resting position of the molded elastomeric material. Thering eventually compresses to the tightest diameter possible and whiledoing so, the spikes engage and interlock with themselves. Onceinterlocked, there is not adequate expansion force from the tissue toenlarge the ring that would allow the spikes to release and slip off ofthe tissue. These spike designs take advantage of the ring having to bestretched open prior to applying to the tissue. Once released, thespikes become locked together and the only way to unlock them is toreexpand the ring, which is not feasible once implanted into the body.

In greater detail, a ring 52 with a toroidal ring body 54 defines athrough-opening 56, and first and second gripping members 58, 60 extenddiametrically across the opening 56 side by side, i.e., are offset fromeach other in the radial dimension defined by the body. The firstgripping member 58 terminates in a distal point 62 as shown, and thefirst gripping member can be urged by tissue through an eye 64 formal inthe second gripping member 60. As shown, in FIG. 3, the first grippingmember 58 is formed offset from the diameter of the ring and isstraightened after molding the body 54 onto the gripping members to aconfiguration in which the first gripping member extends diametricallyacross the through-opening 56 so that it can slide into the eye 64 whenso urged by tissue.

FIGS. 4-9 illustrate various facets of yet another embodiment in which aspike design is shown with an overlapping configuration. The twooverlapping spikes discussed further below prevent each other fromrotating outwards. For the outer spike to rotate inwards, the innerspike must fully rotate inwards to clear the tip of the outer spike in asequential manner, and since this is not how tissue entrapped on thespikes will cause the spikes to react since the outer spike tip does nothave enough force acting on the inner spike to rotate it out of the way,the outer spike remains anchored across the diameter. If the outer spikecannot move, then the inner cannot move and clear first, therebyestablishing an interlocking feature in which each spike lying acrossthe diameter effectively fights each other from movement and slippage.

With more specificity and referring first to FIGS. 4, 5, and 7, a ring70 with a toroidal ring body 72 defines a through-opening 74, and firstand second axially rigid gripping members 76, 78 extend diametricallyacross the opening 56 one over the other, i.e., are offset from eachother in the axial dimension defined by the body. That is, instead ofbeing at the same location along the axis of the ring as in the previousembodiments, in FIGS. 4 and 5 the gripping members are at differentlocations along the axis. As was the case in the examples above, thegripping members 76, 78 shown in FIGS. 4, 5, and 7 each have a fixed endembedded in the body 72 and a free end that is disposed substantiallydiametrically across the through-opening 74 from the fixed end.

As perhaps best shown in FIG. 7, the first gripping member 76 is widerthan the second gripping member 78, and the second gripping member 78can lay flush against the first gripping member 76. In some examples,opposed short triangular stabilizing spikes 80 can have respective fixedends embedded in the body 72 and respective pointed free ends closelyjuxtaposed with the gripping members 76, 78 near the center of thethrough-hole 74. The stabilizing spikes 80 are formed on the ring 70 inan orthogonal relationship to the gripping members 76, 78, extendinginto the through-opening 74.

FIGS. 6-9 are now addressed to illustrate a specialized loading device82 for loading the ring 70 for installation in a patient. Due to theoverlapping gripping members 76, 78 interfering with each other in theresting condition shown in FIG. 7, the first member 76 is wider (or hassome other distinguishing feature) than the second member 78 tofacilitate a loading sequence. Specifically, note in cross-reference toFIGS. 8 and 9 that the loading device 82 is configured to engage androtate the wider gripping member 76 out of the way first (FIG. 8,showing the first member 76 rotated out of the plane defined by the ringbody 72), then the second, thinner gripping member 78 can be rotated(FIG. 9) outwardly from the plane of the body 72. The ring 70 is alsoexpanded at the same time to be fitted on the delivery system as itrides up against a tapered portion 84 of the loading device 82, with thegripping members now rotated out of the plane of the ring such that theycan ride against the device 82 until the body 72 is positioned on alarger cylindrical part 86 of the device 82 in an expanded (stretched)configuration.

In one example, the device 82 may be formed with offset ramp portionsarranged to engage the wider member 76 first and then engage thenarrower member 78. In another example best illustrated in FIG. 6, thedevice 82 is formed with plural axially-oriented slots 88 that are widerthan the second member 78 but narrower than the wider member 76. It willreadily be appreciated that the distal end 90 of the device 82 will thusabut and push the wider member 76 as the ring 70 is slid proximallyrelative to the device 82 onto the device 82, while the narrower member78 remains in the position shown in FIG. 8, riding through one of theslots 88. As the ring 70 is pushed further onto the device 82,eventually the narrower member 78 abuts a slot end 92. Continuedrelative motion from there causes the slot end 92 to push the narrowermember 78 outwardly as shown in FIG. 9.

Turning now to FIGS. 10A and 10B, a spike and tab configuration isshown. A ring 100 has a toroidal ring body 102 defining athrough-opening 104, and a single axially rigid gripping member 106extends diametrically across the opening 104. As shown, the grippingmember 106 is long enough to reach across the diameter of the ring. Themember 106 is also biased at an acute angle relative to the planedefined by the ring body 102 as shown in FIG. 11, and/or is curved so asit penetrates through the tissue, it always ends up on an outer side ofa locking tab 108 which is embedded in the body 102 opposite to thefixed end of the member 106. Subsequently, any tissue movement trying toforce the ring off will cause the free end of the elongated grippingmember 106 to contact the tab 108 and thereby prevent any slippage ofthe ring off of the tissue.

FIGS. 11-13 illustrate a toroidal ring 120 with a ring body 122 defininga through-opening in the manner of the devices disclosed above, exceptthat in FIGS. 11-13 the through-opening is diametrically spanned by aflexible expandable cage structure 124 that is disposed in thethrough-opening as shown with opposed ends 126 embedded in the body 122.The cage structure 124 defines plural openings 128 into which tissue canextend and preferably has a central through-opening which can expandaround the below-described delivery device. The webbed cage structuremay be made similar to a stent using a laser to cut out portions of atube such as but not limited to a nitinol tube, or it may be formed byarranging a wire into a cone-shaped structure. FIG. 13B shows the cage131, which is tapered toward an apex and thus can be regarded asfrusto-conical and in some cases completely conical, may also be formedby laser cutting or photoetching flat stock nitinol or steel andsubsequently rolled to form the desired generally conical shape 133shown in FIG. 13C. FIG. 13D shows silicone rubber is then overmoldedonto the cage to form the body 122. The cage places the triangularspikes at a biased angle against the tissue. Stated differently, thespikes of the cage are oriented toward the long axis defined by thecage. Expulsion forces of the tissue causes these spikes to furtherengage the tissue and become tighter to prevent slippage of the ring.

FIGS. 12 and 13A illustrate operational delivery of the ring 120 toconstrict tissue 130. The ring 120 is stretched over a delivery device132 in an expanded configuration shown in FIG. 12. The delivery device132 is then removed while the ring 120 is held or remains in place tocollapse around the tissue 130 as shown in FIG. 13A, constricting thetissue. The cage structure 124 grips and/or digs into the tissue 130 toprevent slippage of the ring 120 off of the tissue 130.

FIGS. 14A-C and 15A-D show manufacturing steps for making a ring such asany of the rings described above. As shown in FIGS. 14A-C variousgripping member configurations may be used in addition to thosedescribed above. For example, as shown at 140 three gripping members mayextend radially inwardly to almost meet each other, being radiallyspaced apart by 120°. Or, as shown at 142 and 144, four gripping membersmay be arranged at 90° intervals and can extend toward each other at acentral point, with the ends of two opposed members slightly overlappingeach other (142) or with the ends of ail four members almost meetingeach other at a central point (144).

Regardless of the particular gripping member configuration used, it willreadily be appreciated in reference to FIGS. 14A-C that all grippingmembers have respective fixed ends arranged on a circular support 146,with the gripping members extending radially inward relative to thecircular support 146. The circular support and gripping members are madeof a unitary piece of material e.g., stainless steel, by, e.g.,employing laser cutting or photoetching principles.

Next, as shown in the illustration of FIG. 15B, a toroidal resilientring 148 is overmolded onto the support/gripping member assembly. Thus,the support/gripping member assembly may be disposed in a mold having atoroidal cavity formed therein and then fluidic silicone rubber or otherappropriate ring material injected into the cavity and heat cured toform the body 148. Then, as shown in FIGS. 15C and 15D, the grippingmembers and ring are removed from the circular support 146 to establishone of the present tissue gripping rings. Excess ring material may thenbe removed from the gripping members.

Referring briefly to FIG. 20, in one embodiment the overmolding step isexecuted in a mold 150 having first and second parts 152, 154 that whenfacing each other define a toroidal void into which materialestablishing the ring 148 is directed. The mold also is formed withspike channels into which the spikes or gripping members 156 aredisposed prior to overmolding, with the circular support beingsandwiched between the parts 152, 154. After molding, the first part 152is distanced from the second part 154 to expose the ring 148 and spike156.

In the example shown in FIG. 20, if desired ejector pins 160 may beprovided in one of the parts of the mold. Alter distancing the firstpart 152 from the second part 154, the ring may be removed from thesecond part 154 by reciprocating the ejector pins 160 against the ringto push it out of the mold.

FIGS. 16-19 illustrate an assembly including a delivery device 170 ontowhich a ring 172 is to be disposed by pushing the ring 172 onto anexpander tool 174 and then onto the delivery device 170, in some casesusing an elongated axially rigid pusher tool 176. When disposed on thedelivery device 170, the ring is stretched to a radially enlargedconfiguration such that when it is pushed off of the delivery device 170onto tissue, the ring collapses to a relaxed, radially smallerconfiguration around the tissue.

As best shown in FIG. 17, the expander 174 tapers radially outwardlyfrom a first end 176 of the expander to a radially enlarged cylindricalsegment 178, which has substantially the same diameter as the endsegment 180 of the delivery device 170 onto which the ring 172 is to bedisposed. In contrast, the diameter of the end 176 substantially equalsthe diameter of the ring 172 when the ring is in a relaxed state. As thering 172 is pushed from the first end 176 toward the cylindrical segment178, it expands, with the spikes being rotated out of the plane definedby the ring body as they ride against the tapered part of the expander174.

The cylindrical segment 178 of the expander 174 is juxtaposed with thecarrying portion 180 of the delivery device 170 as shown, and then thering 172 is pushed from the cylindrical segment 178 onto the carryingportion 180 (FIG. 18) to load die ring 172 in a stretched state fordelivery to the tissue. The expander 174 is removed and the ring 172 isnow loaded onto the delivery device 170 (FIG. 19). Subsequently, to pushthe ring 172 off of the delivery device, a collar 182 is moved againstthe ring to urge it off of the delivery device, either by pushing thecollar 182 toward the ring or by retracting the carrying portion 180toward the collar.

FIG. 17 perhaps best shows that when it is desired to push the ring ontothe expander and delivery device using the pusher tool 176, the pushertool 176 may be formed with an end segment 184 that in turn is formedwith longitudinal slots 186. The slots 186 enable the end segment 184 toradially expand as the end segment 184 rides over the expander 174 fromthe first end 176 of the expander toward the cylindrical portion 178 ofthe expander.

While the particular DEVICES AND METHODS FOR SECURING TISSUE are hereinshown and described in detail, it is to be understood that the subjectmatter which is encompassed by the present invention is limited only bythe claims.

What is claimed is:
 1. Method for configuring a resilient ring forplacement in a patient to cause the ring to surroundingly grip tissue inthe patient, comprising: engaging the ring with a first end of anexpander, the expander tapering radially outwardly from the first end toa cylindrical segment, a diameter of the first end substantiallyequaling a diameter of the ring when the ring is in a relaxed state;pushing the ring along the expander to radially stretch the ring untilthe ring surrounds the cylindrical segment, wherein the act of pushingis executed using an elongated axially rigid pusher tool, the pushertool having an end segment formed with longitudinal slots to enable theend segment to radially expand as the end segment rides over theexpander from the first end of the expander toward the cylindricalsegment of the expander, the longitudinal slots extending longitudinallyin a direction parallel to the direction the ring is pushed; juxtaposingthe cylindrical segment with a carrying portion of delivery devicehaving substantially the same diameter as the cylindrical segment; andpushing the ring from the cylindrical segment onto the carrying portionto load the ring in a stretched state for delivery to the tissue.
 2. Themethod of claim 1, wherein the delivery device includes a pushing collarhaving a larger radius than the ring when in the stretched state, thepushing collar being axially movable relative to the ring to push thering off the carrying portion onto the tissue.